Can Population III stars be major origins of both merging binary black holes and extremely metal poor stars?
Can Population III stars be major origins of both merging binary black holes and extremely metal poor stars?
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III族恒星能否成为合并双黑洞和金属贫乏恒星的主要起源？
DOI：
10.1093/pasj/psac010
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发表时间：
2022
影响因子：
2.3
通讯作者：
Tominaga Nozomu
中科院分区：
文献类型：
--
作者：
Tanikawa Ataru;Chiaki Gen;Kinugawa Tomoya;Suwa Yudai;Tominaga Nozomu
第三星族星、第一恒星或无金属恒星是由原始气体组成的。我们已经研究了它们是否可以成为合并双黑洞（BH）和极贫金属（EMP）恒星的主要来源。EMP星的丰度模式有助于追溯Pop III星的性质。我们已经证实了以前的论点，观察到的BH合并率需要Pop III星星形成效率比理论预测值大10倍，而宇宙再电离历史仍然允许这样高的Pop III星星形成效率。另一方面，我们新发现EMP星的元素丰度模式只允许Pop III初始质量函数，其最小质量为15- 27 M。换句话说，最小质量必须不偏离临界质量，低于临界质量的Pop III星分别会留下中子星和BH。Pop III星可能仍然是合并二进制BH的主要来源，但我们的研究已经减少了允许的参数空间的假设下，EMP星形成的原始气体混合Pop III超新星喷出物。
Population (Pop) III stars, first stars, or metal-free stars are made of primordial gas. We have examined if they can be dominant origins of merging binary black holes (BHs) and extremely metal-poor (EMP) stars. The abundance pattern of EMP stars is helpful to trace back the properties of Pop III stars. We have confirmed previous arguments that the observed BH merger rate needs Pop III star formation efficiency 10 times larger than theoretically predicted values, while the cosmic reionization history still permits such a high Pop III star formation efficiency. On the other hand, we have newly found that the elemental abundance pattern of EMP stars only allows the Pop III initial mass function with the minimum mass of ∼15–27M. In other words, the minimum mass must not deviate largely from the critical mass below and above which Pop III stars leave behind neutron stars and BHs, respectively. Pop III stars may still be a dominant origin of merging binary BHs but our study has reduced the allowed parameter space under the hypothesis that EMP stars are formed from primordial gas mixed with Pop III supernova ejecta.